This year’s PAX Prime offered up plenty of AAA offerings for attendees to enjoy, but the bread and butter of PAX have always been board games and indie games, even if the convention center layout didn’t do indie developers any favors in terms of giving them the exposure that could lead to that one big break. Anyway, the point is there were quite a few notable indie titles on display at the show, and while I wasn’t able to see them all, I wanted to highlight a couple of the standouts so that you could proptly add them to your radars.

Vessel

This stunning, fluid dynamics-based puzzle platformer has been on our radars for some time now, just around the time it was nominated for Technical Excellence at last year’s Independent Games Festival. At PAX 2011, I was able to finally get my hands on the game, and while I only had about 15 minutes to play, it ended up being my favorite game of the show. The art direction is jaw dropping, due largely to the slick, clean steam punk style that instantly sucks you in, and the level of detail that is packed into each of 2.5D planes is just remarkable.

The gameplay is equally satisfying and quite novel. Since you play as an inventor who has found a way to make creatures called Fluros, which are basically fluid-based machines, you have to use the game’s various, fully simulated liquids to make your way through expansive and diverse settings ranging from massive industrial factories to lush forests. The lighting and texture work (and the physics of course) are just spectacular, and the whole game just pops off the screen.

The puzzles I faced required me to toss down Fluro pods that soak up whatever liquid is nearest to it and then form into fully automated fluid creatures that would make their way to the closest button and hop on top of it to open doors to new areas. What’s especially nifty is that liquids are attracted to the Fluros, which can lead to some fiendishly clever scenarios. In one, I had to redirect a vertical water flow so it snaked around obstructions and was able to collect at the bottom of a tall shaft where it could be gathered up by a Fluro and provide me with my escape. To do this, I had to drop three pods at various platforms attached to the shaft to essentially pull the water in the right direction. It’s in these relatively simple puzzle moments that you realize just how complex and challenging the later stages will no doubt be.

Arkwright, the inventor you play as, also has a device that lets you suck up liquids and spray them wherever you want. For instance, you might have to spray conveyor belts topped with molten steel with water to cool down sections so you can then jump across them without dying. I didn’t get to do this, but judging from the trailer, it looks like you’ll eventually also be using the contraption to fight off enemies and build organic platforms out of the various liquids.

Even from the very little bit I was able to play, it’s clear that Strange Loop Games has a real gem on its hands in Vessel. Hopefully it won’t let all of that potential slip through its fingers when the game is finally released later this year on PSN, Xbox Live, and PC.

Chasing Aurora

Broken Rules Games’ follow up to its gravity-based, world twisting platformer And Yet It Moves is somewhat difficult to classify. For starters, you play as birds, each with its own sense of style (i.e. an eye patch wearing crow). While the game will be primarily a single-player affair, its was the game’s multiplayer that was playable at the show. In this mode, four players face off in a CTF-style match in which each player fights for control over a beacon. You pick up the beacon by flying into it or running into a player who is holding it. To win, you have to be holding the beacon and be the only person on screen for three seconds, which sounds much easier than it actually is, especially when someone decides to catch the beacon on fire and start swirling it around and killing people with it.

The map consists of a number of rock segments of varying heights and depths scattered across the level. There are also currents flowing in various directions at certain points, which can be used to make super quick escapes. You fly around with the left thumbstick, and you tuck in your wings with the right trigger to dive. Because the gameplay is so fast-paced, matches can last anywhere from a couple minutes to a dozen or more depending on the aerial prowess of the players.

Even though birds are all the rage these days, especially in the downloadable space, Chasing Aurora has a certain charm and style that makes me eager to see more of it. The game will be out sometime in 2012.

Airmech

One of the main reasons I’m not a big fan of RTS games is that I can’t stand not being able to completely control an individual character. I hate the idea of putting my fate in the hands of others (I have trust issues, okay?!), so naturally managing troops and sending them off to do my biding without any real control over their moment-to-moment attacks doesn’t really appeal to me.

Thankfully, Carbon’s sci-fi RTS gives me exactly the kind of control I crave while still featuring a robust RTS component that should be familiar to anyone who has seen a real-time strategy game at some point in their life. What makes AirMech particularly compelling is that not only do you pilot one of several different aircrafts (i.e. plane, helicopter, flying saucer) capable of transforming into a mech at the push of a button (both of which fire lasers using the thumbsticks, Geometry Wars-style), but you can also use your ship to pick up units and move them around the battlefield. At the start of the game, you’ll be able to choose from one of a number of different spacecraft, pick your pilot, and select eight units to assist you. Some units are fast and weak, while others are slow and strong. It’s up to you which one is more your style.

The match I watched took place on a desert map that seemed primarily designed to serve as a tutorial since the map was basically a horizontal strip with the player’s bases on the left side and the enemy’s on the right, but it did a fine enough job of getting across the game’s core gameplay hooks. Like any RTS, you have bases that let you build everything from infantry to rocket-mounted trucks to tanks, and what’s great is that once those units are built, you can pick them up from any of your bases, not just the one where you put in the build order. To pick up units, you simply fly over the base, and the unit will rise from inside the building for you to pick it up (left trigger).

You can cue up multiple units at one time, and since you can pick them up from any base, you never feel like you’re just waiting around for units to be built, especially since at any time you can engage the enemy yourself in your ship or on foot. And should you find yourself taking too much damage, you can regenerate health by flying over any of your bases.

Once you have your units, you can then give them orders like defend and attack, standard RTS stuff. Infantry units can infiltrate enemy bases, and if four units make it inside, the base is yours. I didn’t get to see how the entire battle played out, but from I saw, the game looked to have tremendous easy to pick up/hard to put down potential.

Snapshot

Retro Affect has managed to bring something truly fresh to the puzzle-platforming space with its eye-catching, picture-based Snapshot. You play as an adorable robot named Pic who is capable of capturing objects (even things like light and Pic himself) by taking pictures of them and then placing them throughout the world to solve puzzles. It’s a pretty wild mechanic, but after watching it in action for a few minutes, you start to get the hang of it. (See the above trailer.)

What’s particularly cool is that you can actually capture objects in motion as well. For instance, if you drop a box and take a picture of the falling box, the box will shoot out of the picture in the direction it was falling when you place it back in the world. The portion of the demo I saw didn’t include this specific example, so I don’t know exactly how it would factor into solving a puzzle, but it’s a pretty good indication of just how complex the picture mechanic is, even though the section I saw kept things relatively simple.

The hand-drawn animations and environments give the game a wonderfully whimsical feel, and the color pallet is bright and colorful. Combine this style with a refreshing, perspective shifting mechanic that has a very Portal-esque learning curve to it, and you have a recipe for a breakout indie hit.